Nut tightener



Patented Nov. 19, 1946 NUT TIGHTENER John Henry Bueehler, Chicago, Ill.

Application November 13, 1944, Serial No. 563,164

6 Claims.

My invention relates to nut locks, and more vparticularly to devices which are designed to act automatically to tighten or screw down a nut which may become loosened from vibration, and one object is to provide a device of this kind which requires no alteration of the nut.

A `further object is to provide a nut tightener which employs a form or accessory sleeve as its base and for the purpose of imparting the tightening movement to the nut.

Another object is to provide a device of the above character which uses the projecting end of the screw or bolt on which the nut is mounted as an anchor to maintain a torsional iniuence on the nut.

A still further object is to secure the anchor referred to above by means of a slot in the end of the screw or bolt where such end is superiiuous and therefore suffers no weakening influence from the presence of the slot.

An additional object is to provide a nut tightener which can be kept in stock as a unit `for instant application to the nut when required.

An important object of the invention is to constitute the novel tightener in a manner to be pre-wound by means at the factory or plant where it is manufactured and applied to the nut by a simple tool in a manner to transfer its influence to the same.

An essential object of the invention is to construct the same of only two parts, and in a form to be produced at small expense.

With the above objects in View and any others which may suggest themselves from the description to follow, a better understanding of the invention may be had by reference to the accompanying drawing, in which- Fig. 1 is a perspective view of a tool employed to wind the nut tightener;

Fig. 2 is a perspective View of a spring forming one component of the tightener;

Fig. 3 is a similar view of a shell forming the other component thereof;

Fig. 4 is another view showing a die employed for winding of the tightener;

Fig. 5 is a perspective view of a bolt and nut assembly in readiness for the application of the tightener;

Fig. 6 is a perspective view showing the manner in which the container is wound and set; and

Fig. 7 is an elevation of the bolt and nut assembly with the tightener mounted thereon.

In accordance with the foregoing, specific reference to the drawing indicates the first-mentioned component of the tightener as a coil spring I0.

It is noted that the spring is flared upwardly, has its upper end portion II bent in as a cross bar and its lower end portion I2 formed as a hook.

The second component of the nut tightener is in the form of a sleeve I3 of hexagonal design to be suitable to slide over a nut of the same form and approximate size. It is understood that the sleeve may be made square or of any other design to conform to the type of nut it is intended to serve. The topedge I4 of the sleeve is formed with a series of oblique and diametrically paired notches or pockets I5, the `floors of these rising with inclines I5 to the original level of the said top edge. The sleeve also has an outward base flange I 1, one portion of which is raised in the form of `a hump I8 containing a perforation I9 in its crown. The sleeve is of light sheet metal, and may be made in the form of a stamping.`

The coil spring I0 and the sleeve I3 are intended to be joined as a unit which may be kept or stocked in readiness forrapplication to a nut whenever desired. In its normal or original form the spring is taller than the sleeve; and the bottom of the spring is of a diameter to t smoothly around the Y body of the sleeve when the spring is mounted thereon. When this is done, the hook I2 of the spring is caught in the perforation of the sleeve hump I8, as indicated in Fig. 6.

The joining of the spring IB with the sleeve I3 also involves the tensioning of the spring in relation to the sleeve. This is done by winding the spring from the top, and involves the rotation of the spring cross bar Il in a clockwise direction in accordance with Fig. 2. The winding may be done by means of a key-wrench 20 formed with bayonet slots 2| at the bottom, these serving to retain the cross bar II against dropping out of the wrench after the latter has been lowered on the cross bar and given a partial turn. If the winding influence on the sleeve iis too strong for the same to be held by hand, the sleeve may first be mounted on a hexagonal die 22 having a flanged base 23 and forming part of an inverted key-wrench 24. The spring may now be wound to a desired tension and to a point where the cross bar II spans an opposed pair of the sleeve notches I5. The cross bar has sufficient length for this purpose by extending fully across the top spring coil. Downward pressure on the wrench 20 will seat the cross bar in the notches I5, and a backward turn and lift of the wrench will cause it to release the spring. The latter is now wrapped in tensioned relation to the sleeve. It will now be appreciated that the original height and flare of the spring were necessary because 3 the spring not only shortens when its convolutions get closer from winding, but the coils also have a contracting tendency from the winding end, so that the ilares provides suicient room between the spring and the body of the sleevel suitable machine methods, particularly where theA springs are of heavier gage or the required tension stronger.

The application of a nut tightener unit of the above character to the work requires no change in the nut, and only a slight change in the bolt. Thus, an assembly of abolt 25 with a nut 26 tightened on a pair of plates -21 is shown in Fig. 5. The threaded bolt shank 2% rising above the nut is diametrical-ly slotted for the present purpose, as indicated at 329, the Width of the slot being preferably two-thirds the diameter of the bolt shank 23. In application, the tensioned unit of the spring it and sleeve i3 is mounted to seat the sleeve base ilange vIl on the upper plate 2l and the sleeve body around and in iitting relation with the nut. The'key-wrench v2i! is now applied to the spring cross bar H with a winding inuence to raise it out of the notches l5 and o the sleeve. Now the wrench is Veither held or turned to locate the cross bar Vover the slot' 29, depressed to seat thecross bar deeply in the slot, and removed. The

`tension of ther-spring ynow holds its cross bar firmly in the slot, and the sleeve exerts pressure on the nut in the tightening direction. Y rI'hus, should the nut loosen somewhat from vibration or the settling ofthe parts secured by the bolt, the sleeve will instantly tighten the nut and hold such parts secure. f

While 'it may rarely occur, it is possible that over a long period of use the nut tightener may take up loosenessso far as to cause the spring to lose most or all of its tension. In such event, and particularly when the bolt extends at an angle or in a horizontal position, the tightener could slide or fall 01T from vibration or impact by som-e object.

Figs. 5 and 7 show a simple expedient against such an eventuality. Thus, the bolt shank may be made with a cross-bore `Sil near its free end, and a Cotter pin 3i applied after the nut tightener has been tted. In this case the latter can at no time slide or be knocked off` or become lost.

It has been mentioned that the width of the slot is as much as two-thirds of the bolt shank diameter. This allows a wider latitude in the location of the slot by the cross bar l I when the Ytightener is rltted to the nut, so that the slot Iis "found quite readily as the key-Wrench is turned.

It is also possible to apply the tightener Without the use of the key-wrench. Thus, when 'the tightener is positioned with the cross bar il in alinement with the slot 29 and mounted on the nut with pressure, the cross bar will be raised outl of the tightener by the bottom of the slot. The extra width of the latter does not weaken the bolt, since the slot is made in a portion Well beyond the 4 useful or required length of the bolt; and such portion will of course have more strength than necessary to resist the tension of the spring.

It will be evident from the above description that I have provided a nutl tightener which can be kept or stocked as a unit or accessory in the Wound or set condition for use as needed. In such event a simple key-wrench or like implement suffices to t the tightener to the vvork.k It can then remain in place indefinitely, takes up little more room than the nut and will not get out of order or adjustment, acting automatically to take up nut looseness in the event of vibration, settling orfshrinkage of the work or material secured. Also, the Cotter-pin expedient is applicable to insure against the loss of the tightener in any event. Further., the device consists of only two parts made of commonly available materials and capable of being fabricated and assembled by machine methods, so that the tightener may be produced at low cost, to sell in an assortment of sizes vancl'alo'ng with a line 'of slotted vbolts and accessory key-Wrenches to manufacturers and users `of machinery, engines and the like.

While I have described the invention along speciiic lines, various minor changes or refinements may be rnade therein without departing from its principles, and I desire to consider such changes and reiinements as coming Within the scope and spirit of the appended claims.

I claim; v

fl. A pre-set tightenei' for a nut securing work on a (bolt, wherein the free end 'of the latter projects from the -nut and is Vformed with anV "end slot, comprising a member adapted to be mounted .nonrotatably on thenut, andfa woundfco'il spring Ysurrounding the member, the ends of the spring being attached to the member, on'e end 'or the spring being movable from the member and` t l a sleeve with notch means in one end, vand said one end of the spring lbeing 'deposited in said notch means.

'3. vThe structure 'of claim l, Said member being a sleeve with a pair of undercut notches on oli-- ametrically-opposite sides in `one end, and said oneend of theV spring being a cross bar 'deposited in said pair of notches 'and locked in said notches by the tension of the spring.

4. The structure of claim l, said member'being a sleeve with a pair of undercut notches on diametrically-oppo'site sides in one endan-d said one end of the spring being across bar deposited in 'said pair of notches and locked in said notches by the tension of the spring., the floors of the notches extending inclinedly to said end of th sleeve. Y

5. The structure of `claim 1., the spring being ilared in the direction 'of said `end prior t0 being Wound.

6. The structure of claim l, said member 'being a sleeve around the nut, andthe lspringl being taller than the sleeve prior to being wound.

. JOHN HENRY BUECHLERQ 

